June 2021 • Nebraskaland 59
3 feet in height, common fi eld horsetail,
common scouring-rush and smooth
scouring-rush are widespread, growing
on moist shorelines, fl oodplain forests
and wet meadows. Field horsetail is our
only somewhat weedy fern. Spreading
via rhizomes, it forms colonies in
roadsides and crop fi elds where it
draws the ire of farmers. Known from
only a few Sandhills marshes, water
horsetail begins growth submerged in
up to a foot of water before emerging
above the surface.
Many people are familiar with
horsetails and scouring rushes
because of their jointed stems, and
enjoy pulling them apart, joint by joint.
Creative kids have been known to
string the segments together to create
a fern necklace. From a more practical
standpoint, their ridged stems are rich
in silica, and because they often grow
near water, settlers used them to scour
pots and pans. The stems also make a
great emergency fi ngernail fi le.
Equisetum's spore-producing cones,
composed of highly-modifi ed leaves,
are born on stem tips. Unique among
ferns, their spores have four long,
strap-like structures called elaters that
coil and uncoil in response to changes
in humidity. When dry, the elaters
uncoil, creating wind resistance which
helps the spore stay aloft. When the
humidity rises, such as during fog
or after rains, the elaters coil around
the spore and it drops to the ground,
hopefully onto moist soil suitable for
germination.
A New Fern?
Recently, an ecologist sent me
a photo of a fern he encountered
last summer in oak woods at Rock
Glen Wildlife Management Area in
Jeff erson County. Although the photo
is inconclusive, the plant appears to
be of a species of shield fern never
before found in our state. A collection
this coming summer might confi rm
this exciting fi nd. Nebraska's ferns
continue to fascinate.
N
Smooth scouring-rush
growing on a stream bank
in Richardson County.